The present invention relates generally to strollers, and more particularly to a stroller assembly having a wheel brake.
Strollers are used to transport babies, infants, and young children. A stroller includes various components such as a stroller frame, an axle coupled to the frame, a stroller wheel attached to the axle, and a brake assembly to lock the wheel against rotation. In some constructions the wheel rotates with the axle, and in other constructions the wheel rotates about the axle.
Conventional stroller brake assemblies have included several designs. In a first design, a stroller brake system includes a wheel having brake nubs and a brake lever having a brake pinion. A person would use their foot to press down on the brake lever to push the brake pinion into engagement between two brake nubs locking the wheel against rotation, and the person would use their foot under the brake lever to lift up the brake lever to lift the brake pinion out from engagement from between the two brake nubs. In a second design, a stroller wheel brake mechanism includes a pivoting foot pedal which rotates a cam which moves a sharp tip of a cam follower axially between a pair of angularly spaced ribs on the wheel to lock the wheel against rotation. In a third design, when the brake pedal is depressed, a pin extending outwardly from the brake pedal engages radial teeth on the inner center hub to lock the wheel and prevent it from rotating. In a fourth design, a foot pedal is rotated about an axis which is parallel to, but spaced apart from, the wheel axle. The rotating foot pedal rotates an attached brake lever projection into engagement between two adjacent radially-spaced-apart ribs on the wheel locking the wheel against rotation. In a fifth design, an actuation lever pivots a brake member about an axis parallel to, but spaced apart from, the wheel axle. The brake member has a longitudinal projection. The rotating brake member rotates the longitudinal projection into engagement in a gap between two adjacent rib extensions a cog wheel of the stroller wheel. The various designs suffer from one or more problems such as a lack of a foot actuation pedal, an inability of a single foot pedal to actuate the brakes on two wheels, a requirement of strength to engage a pinion in an undersized gap between two adjacent ribs, an awkward engagement of a pin between two adjacent ribs wherein the pin may catch on the side of a rib, and an undesirable lever engagement against the wheel circumference to lock the wheel.
What is needed is a stroller assembly having a wheel brake which avoids the above-mentioned problems found in the wheel brakes of conventional stroller designs.
A first expression of a preferred embodiment of the invention is for a stroller assembly having a stroller frame, an axle coupled to the frame, a stroller wheel, and a brake assembly. The stroller wheel is rotatable about the axle, wherein the wheel has a hub portion, and wherein the hub portion includes a radially-aligned hub slot. The brake assembly includes a cam and a radially-movable pin. The cam is non-rotatably attached to the axle and has a protrusion. The pin has a longitudinal axis aligned substantially parallel to the axle, is positioned to follow the cam, and has a first end which is disposed to radially move into and out from the hub slot. Rotation of the cam causes the pin to outwardly follow the protrusion and move radially outward to a first position. Counter-rotation of the cam causes the pin to inwardly follow the protrusion and move radially inward to a second position. The first position is one of an engagement position and a disengagement position, and the second position is the other of the engagement position and the disengagement position. The engagement position is a position in which the pin is radially engaged in the hub slot to lock the wheel against rotation about the axle. The disengagement position is a position in which the pin is radially disengaged from the hub slot to allow the wheel to rotate about the axle.
A second expression of a preferred embodiment of the invention is for a stroller assembly having a stroller frame, an axle coupled to the stroller frame, a stroller wheel, and a brake assembly. The stroller wheel is rotatable about the axle, wherein the wheel has a first side with a hub portion, and wherein the hub portion includes radially-spaced-apart and radially-aligned ribs. The brake assembly includes a cam and a radially-movable pin. The cam is non-rotatably attached to the axle and has a protrusion. The first side of the wheel faces toward the cam. The pin has a longitudinal axis aligned substantially parallel to the axle, is disposed to follow the cam, and has a first end which is disposed to longitudinally overextend the ribs. Rotation of the cam causes the pin to outwardly follow the protrusion and move radially outward to a first position which is radially beyond the ribs to allow the wheel to rotate about the axle. Counter-rotation of the cam causes the pin to inwardly follow the protrusion and move radially inward to a second position which is between two adjacent ribs to lock the wheel against rotation about the axle.
A third expression of a preferred embodiment of the invention is for a stroller assembly having a stroller frame, an axle coupled to the stroller frame, a stroller wheel, a brake assembly, a housing, and a spring. The stroller wheel is rotatable about the axle, wherein the wheel has a first side with a hub portion, and wherein the hub portion includes radially-spaced-apart and radially-aligned ribs. The brake assembly includes a cam and a radially-movable pin. The cam is non-rotatably attached to the axle and has a protrusion. The first side of the wheel faces toward the cam. The pin has a longitudinal axis aligned substantially parallel to the axle, is disposed to follow the cam, and has a first end which is disposed to longitudinally overextend the ribs. The housing longitudinally surrounds the cam. The spring retained in the housing. Rotation of the cam causes the pin to outwardly follow the protrusion and move radially outward to a first position which is radially beyond the ribs to allow the wheel to rotate about the axle. Counter-rotation of the cam causes the pin to inwardly follow the protrusion and move radially inward to a second position which is between two adjacent ribs to lock the wheel against rotation about the axle. The axle is rotatably attached to the housing. The housing includes a first wall portion disposed to block the protrusion during counter-rotation of the cam to prevent over counter-rotation of the cam when the pin is in the second position. The cam includes a longitudinally-extending flange, and the housing includes a second wall portion disposed to block the flange during rotation of the cam to prevent over rotation of the cam when the pin is in the first position. The spring is disposed to bias the pin toward the second position. The housing has a radially-elongated housing slot, the pin is retained in the housing slot, and the first end of the pin extends outside the housing slot. The protrusion has an end having a concave surface for retaining the pin in the first position.
A fourth expression of a preferred embodiment of the invention is for a brake assembly for a wheel, wherein the wheel is rotatable about an axle, wherein the wheel has a hub portion, wherein the hub portion includes a radially-aligned hub slot, and wherein the brake assembly includes the previously-described cam and the previously-described radially-movable pin of the first expression of a preferred embodiment of the invention.
Several benefits and advantages are derived from the invention. The design of the preferred embodiment of the stroller assembly of the invention allows for non-rotational attachment of a foot pedal to the axle, whereby rotation of a single foot pedal can actuate a brake assembly on at least one wheel on each of the two rear legs of a stroller. The cam-driven, radially-moving pin more easily engages, and disengages from, two adjacent wheel ribs (of the second and third expressions of the preferred embodiment of the invention) than do the pins found in wheel brake mechanisms of conventional strollers.